Heart rate variability behaviour during cardiac resynchronization therapy

Abstract

The influence of cardiac resynchronization therapy (CRT) on heart rate variability (HRV) and therefore on autonomic nervous system in the heart has been discussed recently. Purpose of the study to assess the behaviour of HRV parameters in patients (pts) with chronic heart failure (CHF) treated with CRT therapy in three months follow-up. Methods The study group consisted of 17 pts (3F,14M, aged 53±9 years) with CHF at NYHA class III, EF<35% and significant systolic dyssynchrony of the left ventricle in whom BIV pacemakers InSyncIII (Medtronic) were implanted. HRV “time domain” parameters were calculated based on 24-hour digital Holter monitoring which was performed: before the procedure (I), 3-4(II) days after, 1(III), and 3(IV) months after BIV implantation. View this table: Conclusions The decrease of HRV immediately after BIV implantation and the tendency of HRV improvement during CRT therapy in three months follow-up are observed. CRT therapy may improve the autonomic tone in the heart.